1. Field of the Invention
The invention relates to a process and a device for monitoring the condition of a rotating belt, e.g., felt or wire, used in a paper or cardboard machine.
2. Discussion of Background Information
Sensors have already been used which are moved crosswise to the machine travel direction (CD) over the belt of a paper machine in order to scan it. For example moisture cross profiles of press felts are measured in this way. Until now, approx. 100 to 1000 measured values are recorded over the web width with a scan process. Since the belt, e.g., a felt, rotates several times during a scan process, an average moisture cross profile of the entire felt is obtained. However, differences in the felt condition in the machine travel direction (MD) are not recorded.
A full sheet moisture measurement process is already described in Metso Automation News, Press Release of Jun. 4, 2002, with which process a separation of changes resulting in the machine travel direction and in the crosswise direction is achieved. A web scanner for the online determination of the moisture cross profile of a material web, in particular a paper or cardboard web, across the full web width immediately after the press section is described in ipw November 2001, page 27.
The previous prior art has been concerned exclusively with properties of the material web.